Our Second Test of a Low-Cost, Home-Built Projected Table-Top

For those paying attention, we’ve been working on physical resources–not just digital ones–this month.  If you haven’t looked at our first projector build you can click here.  Since then, we decided to take the basic concept and put a little more engineering into it.

But, first principles… we still wanted to keep the build itself in line with our overarching philosophy:

  1. It has to be economical.  Nothing too expensive.  Like, of course a real “projector mount” would be great, but the cost is a little outside where we wanted to be.  A good ceiling mount would be a hundred bucks, and that doesn’t take into account other things like still needing to mount the mirror.
  2. It has to be very configurable.  We wanted to approach this from the standpoint of a normal gaming group.  What if the ceiling is 9 feet instead of 8?  What if the table is an inch or two taller or shorter?  What if I need to be able to put it up and take it down with ease?  Our builds are trying to stay within the bounds of “adjustable and removable”.
  3. It has to work now and in the future.  In the end, it has to meet the needs of my current projector and (ideally) a new one if I get a new one.  It has to put the image down edge to edge.  It has to freaking work.

So, our second build here–what we did differently:

  • Instead of cobbled together bits from a crafts store, I went to a Home Depot with more of a plan in mind.  Now, keep in mind, out of our last build’s $40–almost half of that was reusable on this project.  The plywood was 8 bucks and it was enough material to make two of these rigs.
  • We saved money by abandoning our Velcro and simply putting in more work drilling holes and making the mirror adjustable with proper holes/notches to move the backboard forward and backward as needed.  The “shelf plugs” (little L-shaped things with a hole on one flat for drilling into a shelf and a peg on the other to push into a hole) were only a couple of bucks.
  • We got a bigger mirror and extended the “arm” length from the base to about a foot or so.  Ultimately, making a 1″ square first surface mirror wasn’t any harder than the 8″ from before.

Full cost?  Actually less than the first build.

The result?

The bigger base allows for far more
The bigger base allows for far more “tinkering” with the image size and angle.

The plywood was a great choice.  Strong as heck and pretty easy to work with (I have some basic tools at my disposal like a good smooth cutting handsaw, a very good quality Dewalt drill, clamps, etc.).  The base is big enough to accommodate a bigger projector than mine and allow me to re-position mine a million difference ways.

In the photo to the right, I even backed it up all the way to push against a chain–the result below (which I didn’t shoot a photo of) ended up being a 54″ wide image that went WAY past my table’s edges–too big.  I had to scoot it forward for a more discreet size.

The larger mirror is movable, one inch increments.  This allowed us to pretty significantly change up the table image size.
The larger mirror is movable, one inch increments. This allowed us to pretty significantly change up the table image size.
We used a 12
We used a 12″ mirror for this one and the quarter inch plywood is very, very strong.
The larger mirror, and the adjustable position of it, meant we could get the image size on the table far larger than the needed 48
The larger mirror, and the adjustable position of it, meant we could get the image size on the table far larger than the needed 48″ if need be. We settled for “edge to edge” 48″ by 36″ image.

The woodwork isn’t really pretty, but then I’m just experimenting for now.  The peg-holes that allow me to move the mirror are perfect.  Ultimately, I was able to move the mirror forward and back (and with the bigger base, could do the same with the projector) and get a whole range of different angles, sizes, and pitches to the image on the table.  This flexibility is exactly what we wanted.  It means we could take this rig to a different house, put four ceiling hooks in (easily done, 12″ square drill at corners), and this would be up and running on a new table in 5-10 minutes.

With the mirror being part of the rig, itself, rather than free hanging separately (which I see many people doing), the whole unit is, basically, always perfectly angled.  And where not, easily adjusted for a wide range of needed positions.

The next projector we plan on trying it going to be something used and second-hand.  Something with a higher resolution.  All in keeping with our “low cost” build strategy.  Ultimately, we want to see if this is just viable as an investment of less than $200 out of pocket for everything.

I think it may be.

You can see, below, the edge-to-edge size (my table is 48″ square in my dining room).  This was perfect for using Roll20.

Edge to Edge (48
Edge to Edge (48″ wide), and enough room in the mirror positioning to get up to 54″ if need be.

You can see, below, the three character tokens (we go with all in Roll20–I know many use minis with the projected image as a map).  The greenish cloud (it’s actually grey, but here its just showing up greenish) is the Ranger’s Obscuring Mists.  The orange crescent is the edge of Spirit Guardians swirling around the Cleric (yellow token).  They’re fighting some zombie Beholders in the caves.  A hard fight.  Lots of fun.

My projector is still just a general, non-HD projector.  Our next build will probably be with a proper HD (1080p) projector.
My projector is still just a general, non-HD projector. Our next build will probably be with a proper HD (1080p) projector.
Beneath the ziggurat of Caldaras, in the caverns of the undead, three heroes have completely changed their attack strategy.
Beneath the ziggurat of Caldaras, in the caverns of the undead, three heroes have completely changed their attack strategy.
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6 comments

    1. Well, that represented it’s own set of issues. A Short Throw could do it, pointing down–but I didn’t have a Short Throw projector and they are a good bit more expensive and less common than conventional ones. If I were to go hunting for a second-hand projector, the market is larger for conventional throw and thus cheaper.

      The conceit of our rig builds is primarily “low cost, robust, adjustable”. Short Throw tosses the first part out.

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  1. If you have a university nearby, check to see if they have a surplus shop. Some guys at work and I picked up 720p projectors for ~$75 each.

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    1. That is dash cunning of you, Robotguy…! I’ll look into that. I hadn’t thought of academia at all–and I used to build colleges… you’re spot on. Commonly, they’ve just got hoards of replaced tech.

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